


Incredibly Loud

by GreyJay



Category: Kamen Rider Build
Genre: Angst, Gentle Kissing, Grief/Mourning, M/M, Survivor Guilt
Language: English
Status: Completed
Published: 2020-10-11
Updated: 2020-10-11
Packaged: 2021-03-07 20:40:52
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,143
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26953777
Author URL: https://archiveofourown.org/users/GreyJay/pseuds/GreyJay
Summary: Sento deals with guilt and grief on a warm summer night.
Relationships: Banjou Ryuuga/Kiryuu Sento, banjou ryuuga/kiryuu sento/sawatari kazumi (implied)
Comments: 3
Kudos: 25





	Incredibly Loud

**Author's Note:**

> I haven't written fanfiction in well over a decade, but Build just hit different, I guess. I started writing this before I watched the New World V-Cinemas, so this takes place between the end of the series and the Cross-Z V-Cinema. 
> 
> I'm a sucker for angst, man.

_I sent him to his death._

It’s a thought that chases itself around and around in Sento’s head in the aftermath. The new world has righted a lot of wrongs, but the blood on Sento’s hands is still there, itching away like Shakespearean tragedy. And of all the blood staining Sento’s hands, Kazumi’s hurts the most. It burns like acid and burrows its roots deep into Sento’s soul. 

Sento had to have _known_ Kazumi would transform with that damn knuckle. What had he been thinking, giving it to him? Banjou had asked him essentially the same thing, and Sento had dodged the question at the time. He didn’t have an answer then, and he cannot find one now.

Most days, Sento tries to soothe the ache by remembering that Kazumi is alive here. The Kazumi he and Banjou had known would still not be here, because he had belonged to that old world. Unlike Sento. Unlike Banjou.

The Kazumi here is a Kazumi who has not suffered unspeakable pain. This is a Kazumi who does not ache so terribly that he sees self-sacrifice as the only way out. This is not _their_ Kazumi.

This line of thought keeps him awake, and he chases it over and over. He’s curled around Banjou, but not even Banjou’s solid warmth can lull him to sleep. There is a hole burning inside of him, and it is shaped like _their_ Kazumi. Sento knows the same hole is festering inside Banjou, even if he won’t come out and say it. Sento can see it in the tense lines of his jaw most days.

_Your fault, Sento._

Sento’s skin crawls. He finally gives up on sleep and slips away, careful not to wake Banjou. Pausing, he turns and tucks the blankets around the musclehead. Sento watches him sleep for a moment before deciding he needs some air.

He dresses and quietly slips out into the warm night. It is both late enough that most people are asleep, but early enough that the early commuters are beginning to rouse. Sento finds he enjoys the relative quiet, and, for a moment, he can breathe again. The moment passes quickly— as moments always do— and, soon, the air is pressing tight against his skin again.

Sento starts walking. 

He makes it two whole steps before someone catches his arm. He knows the strength in those fingers, and, in spite of it all, smiles to himself. The smile flickers out by the time he faces Banjou.

“What?” he asks, and exhaustion sneaks into his voice. He hasn’t slept in...days? Weeks? 

It feels like months.

Banjou frowns, but Sento can make out the worry there, too. Banjou wears his emotions loudly. “Where are you going?” he asks. “It’s late.”

Sento gently removes Banjou’s hand from his arm, squeezing his hand gently before releasing it. “I needed some air. Can’t sleep.”

Sento starts walking again, and Banjou follows. They walk in uncharacteristic silence. Maybe Banjou is as tired as he is. Even so, the air feels a little less tight with Banjou at his side, as if his mere presence carries some of the weight.

“I sent Kazumi to his death,” Sento says after a few quiet minutes.

Banjou stops, and Sento doesn’t notice. Banjou runs to catch up, the sound of his feet hitting concrete like gunshots in the night. He overtakes Sento, pressing his hands to Sento’s shoulders to force him to stop. It’s as if the world stops with them.

“What the hell does that mean?” Banjou spits.

That familiar furrow is between his eyebrows and his mouth is turned down in a frown with which Sento is well acquainted. Confusion and pain that echos Sento’s own dance together there, and Sento’s chest aches.

Banjou lost Kazumi, too, after all.

“The last Lost Bottle,” Sento says. “And the Blizzard Knuckle.”

Guilt on top of guilt on top of guilt. It has been consuming him slowly over the last year, but now it burns through him at twice the speed. He curls his fingers into fists, digging his nails into his palms. He wants to look down or away, but forces himself to face Banjou now.

“Kazumin,” Banjou says, “Made his own decisions.”

It doesn’t sound like Banjou believes it, but Sento can’t really tell if it’s his own perception warping reality. He shakes his head, face screwing into pain. 

“He wouldn’t have _made_ that decision had I not…” Sento’s voice breaks, but he forces the words out. They cut like knives on their way out. “Had I not given him the Blizzard Knuckle. He died because of me.” 

The anger drains from Banjou’s face, and Sento can no longer bear to look at him. He opts, instead, to stare at the concrete beneath their feet. The moment is incredibly loud, as if the world itself is silently screaming.

He’s frozen in that moment for what feels like an eternity before Banjou wraps his arms around him and pulls him close. Sento sinks against him, clutching at him like a drowning man as the tears come.

_You did this. You did this._

A million “ifs" chase themselves around his head. A million scenarios that could have played out. If he hadn’t made the knuckle. If he hadn’t run his damn mouth so carelessly. If he hadn’t…

If.

If.

If.

“Idiot,” Banjou says, and the word is both soft and tight. He holds Sento tighter against himself. “Kazumin—” Banjou’s voice splinters over the name this time, but he recovers and presses on. “Kazumin would have done the same thing if given the chance. You know it. I...I know it.”

Sento shakes his head and earns a thump on the back for his effort.

“Would you have preferred it if you’d let him go on without warning him?” Banjou asks.

“N-No, I—”

Banjou pulls back and catches Sento’s chin then, forcing the scientist to look at him. Banjou’s face is blurry through the tears.

“It’s done,” Banjou says. “It’s done and we can’t change it.” 

These words are surprisingly gentle. Banjou releases Sento’s chin and cups his cheek in his hand now. He kisses Sento, the touch of his lips light, and rests their foreheads together. His arm drops and slips around Sento again.

“He’s alive here,” Banjou breathes. “Even if he isn’t _our_ Kazumin. He’s alive here. And he’s happy.”

It sounds like Banjou is trying to convince himself as much as he’s trying to convince Sento. There is some paltry comfort in knowing that Banjou had the same thought Sento did. Sawatari Kazumi is happy in this world.

Kazumi is dead. Long live Kazumi. May his life be happy and free from the demon scientist and his musclehead partner.

Sento is a selfish creature, though, and he knows that Banjou is, too when Banjou whispers, “I want him back, too, Sento.”


End file.
